Master reference for base station network interface sourced from distributed antenna system

ABSTRACT

A network interface for use within a distributed antenna system, the network interface including circuitry configured to: receive a downlink digital communication signal from an external device external to the distributed antenna system, wherein a reference clock is embedded in the downlink digital communication signal; generate a master reference clock for the distributed antenna system using the reference clock embedded in the downlink digital communication signal; convert the downlink digital communication signal into a downlink signal; communicate the downlink signal toward a remote antenna unit within the distributed antenna system; and wherein the distributed antenna system is configured to distribute the master reference clock to various components of the distributed antenna system to keep the various components of the distributed antenna system locked to a single clock, wherein the various components of the distributed antenna system include the remote antenna unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/030,642 entitled “MASTER REFERENCE FOR BASESTATION NETWORK INTERFACE SOURCED FROM DISTRIBUTED ANTENNA SYSTEM” andfiled on Jul. 9, 2018 which is a continuation application of U.S. patentapplication Ser. No. 14/187,115 entitled “MASTER REFERENCE FOR BASESTATION NETWORK INTERFACE SOURCED FROM DISTRIBUTED ANTENNA SYSTEM” andfiled on Feb. 21, 2014 which claims the benefit of U.S. ProvisionalPatent Application Ser. No. 61/767,968 filed on Feb. 22, 2013, all ofwhich are hereby incorporated herein by reference.

This application is related to the following co-pending United Statespatent application, which is hereby incorporated herein by reference:

U.S. patent application Ser. No. 12/845,060 entitled “DISTRIBUTEDDIGITAL REFERENCE CLOCK” filed on Jul. 28, 2010 and which is referred toherein as the '060 Application.

BACKGROUND

Distributed Antenna Systems (DAS) are used to distribute wireless signalcoverage into building or other substantially closed environments. Forexample, a DAS may distribute antennas within a building. The antennasare typically connected to a radio frequency (RF) signal source, such asa service provider. Various methods of transporting the RF signal fromthe RF signal source to the antenna have been implemented in the art.

SUMMARY

A distributed antenna system includes a first base station networkinterface unit configured to receive first downlink signals from a firstexternal device external to the distributed antenna system and toconvert the first downlink signals into a first downlink data stream; asecond base station network interface unit configured to receive seconddownlink signals from a second external device external to thedistributed antenna system and to convert the second downlink signalsinto a second downlink data stream; and a first remote antenna unitcommunicatively coupled to the first base station network interface unitand configured to receive at least one of the first downlink data streamfrom the first base station network interface unit and a first downlinksignal derived from the first downlink data stream. The first remoteantenna unit has a first radio frequency converter configured to convertat least one of the first downlink data stream and the first downlinksignal derived from the first downlink data stream into a first radiofrequency band signal and a first radio frequency antenna configured totransmit the first radio frequency band signal to a first subscriberunit. The distributed antenna system is configured to transmit a masterreference clock to the first external device.

DRAWINGS

Understanding that the drawings depict only exemplary embodiments andare not therefore to be considered limiting in scope, the exemplaryembodiments will be described with additional specificity and detailthrough the use of the accompanying drawings, in which:

FIGS. 1A-1E are block diagrams of exemplary embodiments of distributedantenna systems;

FIGS. 2A-2J are block diagrams of exemplary embodiments of base stationnetwork interfaces used in distributed antenna systems, such as theexemplary distributed antenna systems in FIGS. 1A-1E;

FIGS. 3A-3C are block diagrams of exemplary embodiments of distributedantenna switches used in distributed antenna systems, such as theexemplary distributed antenna systems in FIGS. 1A-1E;

FIG. 4 is a block diagram of an exemplary embodiment of a master hostunit used in distributed antenna systems, such as the exemplarydistributed antenna systems in FIGS. 1A-1E;

FIG. 5 is a block diagram of an exemplary embodiment of a remote antennaunit used in distributed antenna systems, such as the exemplarydistributed antenna systems in FIGS. 1A-1E;

FIGS. 6A-6C are block diagrams of exemplary embodiments of RF conversionmodules used in remote antenna units of distributed antenna systems,such as the exemplary remote antenna unit in FIG. 5;

FIG. 7 is a block diagram of an exemplary embodiment of a hybriddistributed antenna system;

FIG. 8 is a block diagram of an exemplary embodiment of a hybridexpansion unit used in hybrid distributed antenna systems, such as thehybrid distributed antenna system in FIG. 7;

FIG. 9 is a block diagram of an exemplary embodiment of a remote antennaunit used in hybrid or analog distributed antenna systems, such as theexemplary hybrid distributed antenna system in FIG. 7;

FIGS. 10A-10C are block diagrams of exemplary embodiments of RFconversion modules used in hybrid or analog remote antenna units ofhybrid or analog distributed antenna systems, such as the exemplaryremote antenna unit in FIG. 9; and

FIG. 11 is a flow diagram illustrating one exemplary embodiment of amethod of sourcing a master reference clock for a base station networkinterface from a distributed antenna system.

In accordance with common practice, the various described features arenot drawn to scale but are drawn to emphasize specific features relevantto the exemplary embodiments. Like reference numbers and designations inthe various drawings indicate like elements.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which is shown byway of illustration specific illustrative embodiments. However, it is tobe understood that other embodiments may be utilized and that logical,mechanical, and electrical changes may be made. Furthermore, the methodpresented in the drawing figures and the specification is not to beconstrued as limiting the order in which the individual steps may beperformed. The following detailed description is, therefore, not to betaken in a limiting sense.

The embodiments described below describe a distributed antenna systemand components within the distributed antenna system. The distributedantenna system is connected to a plurality of external devices through aplurality of base station network interface units. In exemplaryembodiments, at least one base station network interface unit of thedistributed antenna system provides a master reference clock to at leastone of the external devices. In exemplary embodiments, the masterreference clock is generated within the distributed antenna system. Inexemplary embodiments, the master reference clock is derived fromanother external device through another base station network interfaceunit.

FIGS. 1A-1E are block diagrams of exemplary embodiments of distributedantenna systems 100. Each of FIGS. 1A-1E illustrates a differentembodiment of a distributed antenna system 100, labeled 100A-100Erespectively.

FIG. 1A is a block diagram of an exemplary embodiment of a distributedantenna system 100, distributed antenna system 100A. Distributed antennasystem 100A includes a plurality of network interfaces 102 (includingnetwork interface 102-1, network interface 102-2, and any amount ofoptional network interfaces 102 through optional network interface102-A), at least one remote antenna unit 104 (including remote antennaunit 104-1 and any amount of optional remote antenna units 104 throughoptional remote antenna unit 104-B), and a distributed switching network106.

Each network interface 102 is communicatively coupled to an externaldevice 108 that is configured to provide signals to be transportedthrough the distributed antenna system 100A to the network interface102. In the forward path, each network interface 102 is configured toreceive signals from at least one external device 108. Specifically,network interface 102-1 is communicatively coupled to external device108-1, network interface 102-2 is communicatively coupled to externaldevice 108-2, and optional network interface 102-A is communicativelycoupled to optional external device 108-A. Each network interface 102 isalso communicatively coupled to the distributed switching network 106across a digital communication link 110. Specifically, network interface102-1 is communicatively coupled to the distributed switching network106 across digital communication link 110-1, network interface 102-2 iscommunicatively coupled to the distributed switching network 106 acrossdigital communication link 110-2, and optional network interface 102-Ais communicatively coupled to the distributed switching network 106across digital communication link 110-A. As described in more detailbelow, each network interface 102 is configured to convert signals fromthe external device 108 to which it is communicatively coupled into adownlink data stream and further configured to communicate the downlinkdata stream to the distributed switching network 106 (either directly orthrough other components of the distributed antenna system 100) across arespective digital communication link 110.

Similarly in the reverse path, in exemplary embodiments each networkinterface 102 is configured to receive uplink data streams across arespective digital communication link 110 from distributed switchingnetwork 106. Each network interface 102 is further configured to convertthe received uplink data stream to signals formatted for the associatedexternal device 108 and further configured to communicate the signalsformatted for the associated external device 108 to the associatedexternal device 108.

Distributed switching network 106 couples the plurality of networkinterfaces 102 with the at least one remote antenna unit 104.Distributed switching network 106 may include one or more distributedantenna switches or other components that functionally distributedownlink signals from the network interfaces 102 to the at least oneremote antenna unit 104. Distributed switching network 106 alsofunctionally distributes uplink signals from the at least one remoteantenna unit 104 to the network interfaces 102. In exemplaryembodiments, the distributed switching network 106 can be controlled bya separate controller or another component of the system. In exemplaryembodiments the switching elements of the distributed switching network106 are controlled either manually or automatically. In exemplaryembodiments, the routes can be pre-determined and static. In otherexemplary embodiments, the routes can dynamically change based on timeof day, load, or other factors.

Each remote antenna unit 104 is communicatively coupled to thedistributed switching network 106 across a digital communication link112. Specifically, remote antenna unit 104-1 is communicatively coupledto the distributed switching network 106 across digital communicationlink 112-1 and optional remote antenna unit 104-B is communicativelycoupled to the distributed switching network 106 across digitalcommunication link 112-B. Each remote antenna unit 104 includescomponents configured for extracting at least one downlink data streamfrom an aggregate downlink data stream and components configured foraggregating at least one uplink data stream into an aggregate uplinkdata stream as well as at least one radio frequency converter configuredto convert between at least one data stream and at least one radiofrequency band and at least one radio frequency antenna 114 configuredto transmit and receive signals in the at least one radio frequency bandto at least one subscriber unit 116.

In the downstream, each remote antenna unit 104 is configured to extractat least one downlink data stream from the downlink aggregate datastream. Each remote antenna unit 104 is further configured to convertthe at least one downlink data stream into a downlink radio frequency(RF) signal in a radio frequency band. In exemplary embodiments, thismay include digital to analog converters and oscillators. Each remoteantenna unit 104 is further configured to transmit the downlink radiofrequency signal in the radio frequency band to at least one subscriberunit using at least one radio frequency antenna 114. In a specificexemplary embodiment, remote antenna unit 104-1 is configured to extractat least one downlink data stream from the downlink aggregate datastream received from the distributed antenna switch 102 and furtherconfigured to convert the at least one downlink data stream into adownlink radio frequency signal in a radio frequency band. Remoteantenna unit 104-1 is further configured to transmit the downlink radiofrequency signal in a radio frequency band using a radio frequency bandantenna 114-1 to at least one subscriber unit 116-1. In exemplaryembodiments, remote antenna unit 104-1 is configured to extract aplurality of downlink data streams from the downlink aggregate datastream received from the distributed switching network 106 andconfigured to convert the plurality of downlink data streams to aplurality of downlink radio frequency signals. In exemplary embodimentswith a plurality of radio frequency signals, the remote antenna unit104-1 is further configured to transmit the downlink radio frequencysignal in at least one radio frequency band to at least subscriber unit116-1 using at least radio frequency antenna 114-1. In exemplaryembodiments, the remote antenna unit 104-1 is configured to transmit onedownlink radio frequency signal to one subscriber unit 116-1 using anantenna 114-1 and another radio frequency signal to another subscriberunit 116-D using another antenna 114-C. In exemplary embodiments, othercombinations of radio frequency antennas 114 and other components areused to communicate other combinations of radio frequency signals inother various radio frequency bands to various subscriber units 116.

Similarly in the reverse path, in exemplary embodiments each remoteantenna unit 104 is configured to receive uplink radio frequency signalsfrom at least one subscriber unit 116 using at least one radio frequencyantenna 114. Each remote antenna unit 104 is further configured toconvert the radio frequency signals to at least one uplink data stream.Each remote antenna unit 104 is further configured to aggregate the atleast one uplink data stream into an aggregate uplink data stream andfurther configured to communicate the aggregate uplink data streamacross at least one digital communication link 112 to the distributedswitching network 106.

In exemplary embodiments, a master reference clock is distributedbetween the various components of the distributed antenna system 100A tokeep the various components locked to the same clock. In exemplaryembodiments, a master reference clock is provided to at least oneexternal device 108 via at least one network interface 102 so that theexternal device can lock to the master reference clock as well. In otherexemplary embodiments, the master reference clock is provided from atleast one external device to the distributed antenna system 100A via atleast one network interface 102. In exemplary embodiments, the masterreference clock is generated within a component of the distributedantenna system, such as a network interface 102, a remote antenna unit104, or somewhere within the distributed switching network 106.

FIG. 1B is a block diagram of an exemplary embodiment of a distributedantenna system 100, distributed antenna system 100B. Distributed antennasystem 100B includes a plurality of network interfaces 102 (includingnetwork interface 102-1, network interface 102-2, and any amount ofoptional network interfaces 102 through optional network interface102-A), at least one remote antenna unit 104 (including remote antennaunit 104-1 and any amount of optional remote antenna units 104 throughoptional remote antenna unit 104-B), and a distributed switching network106. Distributed antenna system 100B includes similar components todistributed antenna system 100A and operates according to similarprinciples and methods as distributed antenna system 100A describedabove. The difference between distributed antenna system 100B anddistributed antenna system 100A is that both digital communication links110 and digital communication links 112 are optical communication links.

FIG. 1C is a block diagram of an exemplary embodiment of a distributedantenna system 100, distributed antenna system 100C. Distributed antennasystem 100C includes a plurality of network interfaces 102 (includingnetwork interface 102-1, network interface 102-2, and any amount ofoptional network interfaces 102 through optional network interface102-A), at least one remote antenna unit 104 (including remote antennaunit 104-1 and any amount of optional remote antenna units 104 throughoptional remote antenna unit 104-B), and a distributed antenna switch118A. Distributed antenna system 100C includes similar components todistributed antenna system 100A and operates according to similarprinciples and methods as distributed antenna system 100A describedabove. The difference between distributed antenna system 100B anddistributed antenna system 100A is that both digital communication links110 and digital communication links 112 are optical communication linksand that a distributed antenna switch 118A replaces the distributedswitching network 106. Each network interface 102 is communicativelycoupled to the distributed antenna switch 118A across a digitalcommunication medium 110. Each antenna unit 104 is also communicativelycoupled to the distributed antenna switch 118A across a digitalcommunication medium 110. In exemplary embodiments, the distributedantenna switch 118A can be controlled by a separate controller oranother component of the system. In exemplary embodiments thedistributed antenna switch 118A is controlled either manually orautomatically. In exemplary embodiments, the routes can bepre-determined and static. In other exemplary embodiments, the routescan dynamically change based on time of day, load, or other factors.

In the forward path, the distributed antenna switch 118A distributesand/or routes downlink signals received from the network interfaces 102to the at least one remote antenna unit 104. In exemplary embodiments,downlink data streams from a plurality of network interfaces areaggregated by the distributed antenna switch into an aggregate downlinkdata stream that is communicated to the at least one remote antenna unit104. In the reverse path, the distributed antenna switch 118Adistributes and/or routes uplink signals received from the at least oneremote antenna unit 104 to the plurality of network interfaces 102. Inexemplary embodiments, an aggregate uplink data stream from at least oneremote antenna unit 104 is split apart into a plurality of uplink datastreams by the distributed antenna switch 118A and communicated to theplurality of network interfaces 102.

FIG. 1D is a block diagram of an exemplary embodiment of a distributedantenna system 100, distributed antenna system 100D. Distributed antennasystem 100D includes a master host unit 120 having a plurality ofnetwork interfaces 102 (including network interface 102-1, networkinterface 102-2, and any amount of optional network interfaces 102through optional network interface 102-A), a distributed antenna switch118B, at least one remote antenna unit 104 (including remote antennaunit 104-1 and any amount of optional remote antenna units 104 throughoptional remote antenna unit 104-B), and a distributed switching network106. Distributed antenna system 100C includes similar components todistributed antenna systems 100A-100C and operates according to similarprinciples and methods as distributed antenna systems 100A-100Cdescribed above. The difference between distributed antenna system 100Dand distributed antenna system 100C is that the network interfaces 102and the distributed antenna switch 118B are included within a masterhost unit that is communicatively coupled to the remote antenna units104 by the distributed switching network 106. In exemplary embodiments,the distributed antenna switch 118B can be controlled by a separatecontroller or another component of the system. In exemplary embodimentsthe distributed antenna switch 118B is controlled either manually orautomatically. In exemplary embodiments, the routes can bepre-determined and static. In other exemplary embodiments, the routescan dynamically change based on time of day, load, or other factors.

In the forward path, the distributed antenna switch 118B distributesand/or routes downlink signals received from the network interfaces 102to the at least one remote antenna unit 104 through the distributedswitching network 106. In exemplary embodiments, downlink data streamsfrom a plurality of network interfaces are aggregated by the distributedantenna switch 118B into an aggregate downlink data stream that iscommunicated to the at least one remote antenna unit 104 via thedistributed switching network. In the reverse path, the distributedantenna switch 118A distributes and/or routes uplink signals receivedfrom the at least one remote antenna unit 104 to the plurality ofnetwork interfaces 102. In exemplary embodiments, an aggregate uplinkdata stream received from at least one remote antenna unit 104 via thedistributed switching network 106 is split apart into a plurality ofuplink data streams by the distributed antenna switch 118B andcommunicated to the plurality of network interfaces 102.

FIG. 1E is a block diagram of an exemplary embodiment of a distributedantenna system 100, distributed antenna system 100E. Distributed antennasystem 100E includes a master host unit 120 having a plurality ofnetwork interfaces 102 (including network interface 102-1, networkinterface 102-2, and any amount of optional network interfaces 102through optional network interface 102-A), a distributed antenna switch118C, at least one remote antenna unit 104 (including remote antennaunit 104-1 and any amount of optional remote antenna units 104 throughoptional remote antenna unit 104-B), and a distributed switching network106. Distributed antenna system 100E includes similar components todistributed antenna systems 100A-100D and operates according to similarprinciples and methods as distributed antenna systems 100A-100Ddescribed above. The difference between distributed antenna system 100Eand distributed antenna system 100D is that digital communication links112 are optical communication links.

FIGS. 2A-2J are block diagrams of exemplary embodiments of base stationnetwork interfaces 102 used in distributed antenna systems, such as theexemplary distributed antenna systems 100 described above. Each of FIGS.2A-2J illustrates a different embodiment of a type of base stationnetwork interface 102, labeled 104A-104D respectively.

FIG. 2A is a block diagram of an exemplary embodiment of a base stationnetwork interface 102, general base station network interface 102A.General base station network interface 102A includes signal to datastream conversion module 202A, network interface clock unit 204A,optional processor 206, optional memory 208, and optional power supply210. In exemplary embodiments, signal to data stream conversion module202A is communicatively coupled to an external device output 212A of anexternal device 108A. Signal to data stream conversion module 202A isalso communicatively coupled to at least one digital communication link110. In exemplary embodiments, the digital communication link 110 is anoptical communication link across a fiber optic cable, though it canalso be other types of wired or wireless links in other embodiments. Inexemplary embodiments, the signal to data stream conversion module 202Aand/or the network interface clock unit 204A are implemented usingoptional processor 206 and optional memory 208. In exemplaryembodiments, the optional power supply 210 provides power to the variouselements of the base station network interface 102A.

In the downlink, signal to data stream conversion module 202A isconfigured to receive downlink signals from the external device output212A of the external device 108A. The signal to data stream conversionmodule 202A is further configured to convert the received downlinksignals to a downlink data stream. In exemplary embodiments, the signalto data stream conversion module 202A further converts the data streamfrom electrical signals to optical signals for output on digitalcommunication link 110. In other embodiments, the data stream istransported using a conductive communication medium, such as coaxialcable or twisted pair, and the optical conversion is not necessary.

In the uplink, signal to data stream conversion module 202A isconfigured to receive an uplink data stream from digital communicationlink 110. In exemplary embodiments where digital communication link 110is an optical medium, the radio frequency to optical data streamconversion module 202A is configured to convert the uplink data streambetween received optical signals and electrical signals. In otherembodiments, the data stream is transported using a conductivecommunication medium, such as coaxial cable or twisted pair, and theoptical conversion is not necessary. The signal to data streamconversion module 202A is further configured to convert the uplink datastream to uplink signals. Signal to data stream conversion module 202Ais further configured to communicate the uplink signals to the externaldevice output 212A of the external device 108A.

In exemplary embodiments, the network interface clock unit 204A iscommunicatively coupled to an external device clock unit 214A of theexternal device 108A. In exemplary embodiments, a master reference clockis provided to the external device clock unit 214A of the externaldevice 108A from the network interface clock unit 204A of the basestation network interface 102A. In other exemplary embodiments, a masterreference clock is provided from the external device clock unit 214A ofthe external device 108A to the network interface clock unit 204A of thebase station network interface 102A.

FIG. 2B is a block diagram of an exemplary embodiment of a type of basestation interface 102, general base station network interface 102B.General base station network interface 102B includes signal to datastream conversion module 202B, network interface clock unit 204B,optional processor 206, optional memory 208, and optional power supply210. Similarly to general base station network interface 102A, signal todata stream conversion module 202B is communicatively coupled to anexternal device output 212B of an external device 108B. In contrast togeneral base station network interface 102A, base station networkinterface clock unit 204B is not coupled directly to external deviceclock unit 214B of external device 108B to provide the master referenceclock to the external device 108B. Instead, network interface clock unit204B provides the master reference clock to the signal to data streamconversion module 202B and the master reference clock is embedded in theupstream signal from the signal to data stream conversion module 202B tothe external device output 212B of external device 108B.

In particular, uplink signals can be clocked using the master clock,such that the master clock is embedded in the uplink signals. Then,external device clock unit 214B extracts the master clock from uplinksignals and distributes the master clock as appropriate in the externaldevice 108B to establish a common clock with the distributed antennasystem in the external device 108B. In exemplary embodiments where themaster reference clock is provided from an external device 108B to thedistributed antenna system, the master reference clock can be embeddedin the downlink signals by the external device clock unit 214B so thatthe downlink signals communicated from the external device output 212Bof the external device 108B to the signal to data stream conversionmodule 202B can be extracted by the network interface clock unit 204Band distributed as appropriate within the network interface 102B and thedistributed antenna system 100 generally.

In exemplary embodiments, the signal to data stream conversion module202B and/or the network interface clock unit 204B are implemented usingoptional processor 206 and optional memory 208. In exemplaryembodiments, the optional power supply 210 provides power to the variouselements of the base station network interface 102B.

FIG. 2C is a block diagram of an exemplary embodiment of a type of basestation network interface 102, radio frequency (RF) network interface102C. Radio frequency network interface 102C includes a radio frequency(RF) to data stream conversion module 202C, a radio frequency (RF)network interface clock unit 204C, an optional processor 206, optionalmemory 208, and an optional power supply 210. In exemplary embodiments,radio frequency (RF) to data stream conversion module 202C iscommunicatively coupled to a radio frequency (RF) base station output212C of an external device that is a radio frequency base station 108C.Radio frequency to data stream conversion module 202C is alsocommunicatively coupled to at least one digital communication link 110.In exemplary embodiments, the radio frequency to data stream conversionmodule 202C and/or the radio frequency network interface clock unit 204Care implemented using optional processor 206 and optional memory 208. Inexemplary embodiments, the optional power supply 210 provides power tothe various elements of the radio frequency network interface 102C.

In the downlink, radio frequency to data stream conversion module 202Cis configured to receive radio frequency signals from the radiofrequency base station output 212C of the radio frequency base station108C. The radio frequency to data stream conversion module 202C isfurther configured to convert the received radio frequency signals to adownlink data stream. In exemplary embodiments, this is done usingoscillators and mixers. In exemplary embodiments, the radio frequency todata stream conversion module 202C further converts the data stream fromelectrical signals to optical signals for output on digitalcommunication link 110. In other embodiments, the data stream istransported using a conductive communication medium, such as coaxialcable or twisted pair, and the optical conversion is not necessary.

In the uplink, radio frequency to data stream conversion module 202C isconfigured to receive a data stream across digital communication link110. In exemplary embodiments where digital communication link 110 is anoptical medium, the radio frequency to data stream conversion module202C is configured to convert the uplink data streams between receivedoptical signals and electrical signals. In other embodiments, the datastream is transported using a conductive communication medium, such ascoaxial cable or twisted pair, and the optical conversion is notnecessary. The radio frequency to data stream conversion module isfurther configured to convert the uplink data stream to radio frequencysignals. In exemplary embodiments, this is done using oscillators andmixers. Radio frequency to data stream conversion module 202C is furtherconfigured to communicate the uplink radio frequency signals to theradio frequency base station output 212C of the radio frequency basestation 108C.

In exemplary embodiments, the radio frequency network interface clockunit 204C is communicatively coupled to a radio frequency base stationclock unit 214C of the radio frequency base station 108C. In exemplaryembodiments, a master reference clock is provided to the radio frequencybase station clock unit 214C of the radio frequency base station 108Cfrom the radio frequency network interface clock unit 204C of the basestation network interface 102C. In other exemplary embodiments, a masterreference clock is provided from the radio frequency base station clockunit 214C of the radio frequency base station 108C to the radiofrequency network interface clock unit 204C of the radio frequencynetwork interface 102C.

FIG. 2D is a block diagram of an exemplary embodiment of a type of basestation interface 102, radio frequency (RF) network interface 102D.Radio frequency network interface 102D includes a radio frequency (RF)to data stream conversion module 202D, a radio frequency (RF) networkinterface clock unit 204D, an optional processor 206, optional memory208, and an optional power supply 210. Similarly to radio frequencynetwork interface 102C, radio frequency (RF) to data stream conversionmodule 202D is communicatively coupled to a radio frequency (RF) basestation output 212D of an external device that is a radio frequency basestation 108D and to at least one digital communication link 110. Incontrast to radio frequency network interface 102C, radio frequencynetwork interface clock unit 204D is not coupled directly to radiofrequency base station clock unit 214D of radio frequency base station108D to provide and/or receive the master reference clock to/from theradio frequency base station 108D. Instead, radio frequency networkinterface clock unit 204C provides the master reference clock to theradio frequency to data stream conversion module 202D and the masterreference clock is embedded in upstream signals from the radio frequencyto data stream conversion module 202D to the radio frequency basestation output 212D of radio frequency base station 108D.

In particular, uplink signals can be clocked using the master clock,such that the master clock is embedded in the uplink signals. Then,radio frequency base station clock unit 214D extracts the master clockfrom uplink signals and distributes the master clock as appropriate inthe radio frequency base station 108D to establish a common clock withthe distributed antenna system 100 in the radio frequency base station108D. In exemplary embodiments where the master reference clock isprovided from the radio frequency base station 108D to the distributedantenna system, the master reference clock can be embedded in thedownlink signals by the radio frequency base station clock unit 214D sothat the downlink signals communicated from the radio frequency basestation output 212D of the radio frequency base station 108D to theradio frequency to data stream conversion module 202D can be extractedby the radio frequency network interface clock unit 204D and distributedas appropriate within the radio frequency network interface 102D and thedistributed antenna system 100 generally.

In exemplary embodiments, the radio frequency to data stream conversionmodule 202D and/or the radio frequency network interface clock unit 204Dare implemented using optional processor 206 and optional memory 208. Inexemplary embodiments, the optional power supply 210 provides power tothe various elements of the base station network interface 102D.

FIG. 2E is a block diagram of an exemplary embodiments of a type of basestation network interface 102, baseband network interface 102E. Basebandnetwork interface 102E includes a baseband to data stream conversionmodule 202E, a baseband network interface clock unit 204E, an optionalprocessor 206, optional memory 208, and an optional power supply 210. Inexemplary embodiments, baseband to data stream conversion module 202E iscommunicatively coupled to a baseband base station output 212E of anexternal device that is a baseband base station 108E. Baseband to datastream conversion module 202E is also communicatively coupled to atleast one digital communication link 110. In exemplary embodiments, thebaseband to data stream conversion module 202E and/or the basebandnetwork interface clock unit 204E are implemented using optionalprocessor 206 and optional memory 208. In exemplary embodiments, theoptional power supply 210 provides power to the various elements of thebaseband network interface 102E.

In the downlink, baseband to data stream conversion module 202E isconfigured to receive baseband mobile wireless access signals (such asI/Q data) from a baseband base station output 212E of a baseband basestation 108E. The baseband to data stream conversion module 202E isfurther configured to convert the received baseband mobile wirelessaccess signals to a downlink data stream. In exemplary embodiments, thebaseband to data stream conversion module 202E further converts the datastream from electrical signals to optical signals for output on thedigital communication link 110. In other embodiments, the data stream istransported using a conductive communication medium, such as coaxialcable or twisted pair, and the optical conversion is not necessary.

In the uplink, baseband to data stream conversion module 202E isconfigured to receive a data stream across digital communication link110. In exemplary embodiments where digital communication link 110 is anoptical medium, the baseband to data stream conversion module 202E isconfigured to convert the uplink data stream between received opticalsignals and electrical signals. In other embodiments, the data stream istransported using a conductive communication medium, such as coaxialcable or twisted pair, and the optical conversion is not necessary. Thebaseband to data stream conversion module 202E is further configured toconvert the uplink data stream to uplink baseband wireless accesssignals. Baseband to data stream conversion module 202E is furtherconfigured to communicate the uplink baseband wireless access signals tothe baseband base station output 212E.

In exemplary embodiments, the baseband network interface clock unit 204Eis communicatively coupled to a baseband base station clock unit 214E ofthe baseband base station 108E. In exemplary embodiments, a masterreference clock is provided to the baseband base station clock unit 214Eof the baseband base station 108E from the baseband network interfaceclock unit 204E of the baseband network interface 102E. In otherexemplary embodiments, a master reference clock is provided from thebaseband base station clock unit 214E of the baseband base station 108Eto the baseband network interface clock unit 204E of the basebandnetwork interface 102E.

FIG. 2F is a block diagram of an exemplary embodiment of a type of basestation interface 102, baseband network interface 102F. Baseband networkinterface 102F includes a baseband to data stream conversion module202F, a baseband network interface clock unit 204F, an optionalprocessor 206, optional memory 208, and an optional power supply 210.Similarly to baseband network interface 102E, baseband to data streamconversion module 202F is communicatively coupled to a baseband basestation output 212F of an external device that is a baseband basestation 108F and to at least one digital communication link 110. Incontrast to baseband network interface 102E, baseband network interfaceclock unit 204F is not coupled directly to baseband base station clockunit 214F of baseband base station 108F to provide and/or receive themaster reference clock to/from the baseband base station 108F. Instead,baseband network interface 102F provides the master reference clock tothe baseband to data stream conversion module 202F and the masterreference clock is embedded in upstream signals from the baseband todata stream conversion module 202F to the baseband base station output212F of baseband base station 108F.

In particular, uplink signals can be clocked using the master clock,such that the master clock is embedded in the uplink signals. Then,baseband base station clock unit 214F extracts the master clock fromuplink signals and distributes the master clock as appropriate in thebaseband base station 108F to establish a common clock with thedistributed antenna system 100 in the baseband base station 108F. Inexemplary embodiments where the master reference clock is provided fromthe baseband base station 108F to the distributed antenna system, themaster reference clock can be embedded in the downlink signals by thebaseband base station clock unit 214F so that the downlink signalscommunicated from the baseband base station output 212F of the basebandbase station 108F to the baseband to data stream conversion module 202Fcan be extracted by the baseband network interface clock unit 204F anddistributed as appropriate within the baseband network interface 102Fand the distributed antenna system generally.

In exemplary embodiments, the baseband to data stream conversion module202F and/or the baseband network interface clock unit 204F areimplemented using optional processor 206 and optional memory 208. Inexemplary embodiments, the optional power supply 210 provides power tothe various elements of the baseband network interface 102F.

FIG. 2G is a block diagram of an exemplary embodiment of a type of basestation network interface 102, Common Public Radio Interface (CPRI)network interface 102G. CPRI network interface 102G includes a CPRI todata stream conversion module 202G, a CPRI network interface clock unit204G, an optional processor 206, optional memory 208, and an optionalpower supply 210. In exemplary embodiments, CPRI to data streamconversion module 202G is communicatively coupled to a CPRI base stationoutput 212G of an external device that is a CPRI base station 108G. CPRIto data stream conversion module 202G is also communicatively coupled toat least one digital communication link 110. In exemplary embodiments,the CPRI to data stream conversion module 202G and/or the CPRI networkinterface clock unit 204G are implemented using optional processor 206and optional memory 208. In exemplary embodiments, the optional powersupply 210 provides power to the various elements of the CPRI networkinterface 102G.

In the downlink, CPRI to data stream conversion module 202G isconfigured to receive CPRI signals from the CPRI base station output212G. The CPRI to data stream conversion module 202G is furtherconfigured to convert the received CPRI signals to a downlink datastream. In exemplary embodiments, the CPRI to data stream conversionmodule 202G further converts the data stream from electrical signals tooptical signals for output on the digital communication link 110. Inother embodiments, the data stream is transported using a conductivecommunication medium, such as coaxial cable or twisted pair, and theoptical conversion is not necessary.

In the uplink, CPRI to data stream conversion module 202C is configuredto receive a data stream across digital communication link 110. Inexemplary embodiments where digital communication link 110 is an opticalmedium, the CPRI to data stream conversion module 202G is configured toconvert the uplink data stream between received optical signals andelectrical signals. In other embodiments, the data stream is transportedusing a conductive communication medium, such as coaxial cable ortwisted pair, and the optical conversion is not necessary. The CPRI todata stream conversion module 202G is further configured to convert theuplink data stream to uplink CPRI signals. CPRI to data streamconversion module 202G is further configured to communicate the uplinkCPRI signal to the CPRI base station output 212G.

In exemplary embodiments, the CPRI network interface clock unit 204G iscommunicatively coupled to a CPRI base station clock unit 214G of theCPRI base station 108G. In exemplary embodiments, a master referenceclock is provided to the CPRI base station clock unit 214G of the CPRIbase station 108G from the CPRI network interface clock unit 204G of theCPRI network interface 102G. In other exemplary embodiments, a masterreference clock is provided from the CPRI base station clock unit 214Gof the CPRI base station 108G to the CPRI network interface clock unit204E of the CPRI network interface 102G.

FIG. 2H is a block diagram of an exemplary embodiment of a type of basestation interface 102, CPRI network interface 102H. CPRI networkinterface 102H includes a CPRI to data stream conversion module 202H, aCPRI network interface clock unit 204H, an optional processor 206,optional memory 208, and an optional power supply 210. Similarly to CPRInetwork interface 102G, CPRI to data stream conversion module 202H iscommunicatively coupled to a CPRI base station output 212H of anexternal device that is a CPRI base station 108H and to at least onedigital communication link 110. In contrast to CPRI network interface102G, CPRI network interface clock unit 204H is not coupled directly toCPRI base station clock unit 214G of CPRI base station 108H to provideand/or receive the master reference clock to/from the CPRI base station108H. Instead, CPRI network interface 102H provides the master referenceclock to the CPRI to data stream conversion module 202H and the masterreference clock is embedded in upstream signals from the CPRI to datastream conversion module 202H to the CPRI base station output 212H ofCPRI base station 108H.

In particular, uplink signals can be clocked using the master clock,such that the master clock is embedded in the uplink signals. Then, CPRIbase station clock unit 214H extracts the master clock from uplinksignals and distributes the master clock as appropriate in the CPRI basestation 108H to establish a common clock with the distributed antennasystem 100 in the CPRI base station 108H. In exemplary embodiments wherethe master reference clock is provided from the CPRI base station 108Hto the distributed antenna system 100, the master reference clock can beembedded in the downlink signals by the CPRI base station clock unit214H so that the downlink signals communicated from the CPRI basestation output 212H of the CPRI base station 108H to the CPRI to datastream conversion module 202H can be extracted by the CPRI networkinterface clock unit 204H and distributed as appropriate within the CPRInetwork interface 102H and the distributed antenna system 100 generally.

In exemplary embodiments, the CPRI to data stream conversion module 202Hand/or the CPRI network interface clock unit 204H are implemented usingoptional processor 206 and optional memory 208. In exemplaryembodiments, the optional power supply 210 provides power to the variouselements of the CPRI network interface 102H.

FIG. 2I is a block diagram of an exemplary embodiment of a type of basestation network interface 102, Ethernet network interface 102I. Ethernetnetwork interface 102I includes an Ethernet to data stream conversionmodule 202I, an Ethernet network interface clock unit 204I, an optionalprocessor 206, optional memory 208, and an optional power supply 210. Inexemplary embodiments, Ethernet to data stream conversion module 202I iscommunicatively coupled to an Ethernet output 212I of an external devicethat is an Ethernet adapter 108I to an internet protocol (IP) basednetwork. Ethernet to data stream conversion module 202I is alsocommunicatively coupled to at least one digital communication link 110.In exemplary embodiments, the Ethernet to data stream conversion module202I and/or the Ethernet network interface clock unit 204I areimplemented using optional processor 206 and optional memory 208. Inexemplary embodiments, the optional power supply 210 provides power tothe various elements of the Ethernet network interface 102I.

In the downlink Ethernet to data stream conversion module 202I isconfigured to receive internet protocol packets from the Ethernet output212I. The Ethernet to data stream conversion module 202I is furtherconfigured to convert the internet protocol packets to a downlink datastream. In exemplary embodiments, the Ethernet to data stream conversionmodule 202I further converts the data stream from electrical signals tooptical signals for output on the digital communication link 110. Inother embodiments, the data stream is transported using a conductivecommunication medium, such as coaxial cable or twisted pair, and theoptical conversion is not necessary.

In the uplink, Ethernet to data stream conversion module 202I isconfigured to receive a data stream across digital communication link110. In exemplary embodiments where digital communication link 110 is anoptical medium, the Ethernet to data stream conversion module 202I isconfigured to convert the uplink data stream between received opticalsignals and electrical signals. In other embodiments, the data stream istransported using a conductive communication medium, such as coaxialcable or twisted pair, and the optical conversion is not necessary. TheEthernet to data stream conversion module 202I is further configured toconvert the uplink data stream to uplink Ethernet frames. Ethernet todata stream conversion module 202I is further configured to communicatethe uplink Ethernet frames to the Ethernet output 204I.

In exemplary embodiments, the Ethernet network interface clock unit 204Iis communicatively coupled to an Ethernet adapter clock unit 214I of theEthernet adapter 108I. In exemplary embodiments, a master referenceclock is provided to the Ethernet adapter clock unit 214I of theEthernet adapter 108I from the Ethernet network interface clock unit204I of the Ethernet network interface 102I. In other exemplaryembodiments, a master reference clock is provided from the Ethernetadapter clock unit 214I of the Ethernet adapter 108I to the Ethernetnetwork interface clock unit 204I of the Ethernet network interface102I.

FIG. 2J is a block diagram of an exemplary embodiments of a type of basestation interface 102, an Ethernet network interface 102J. Ethernetnetwork interface 102J includes an Ethernet to data stream conversionmodule 202J, an Ethernet network interface clock unit 204J, an optionalprocessor 206, optional memory 208, and an optional power supply 210.Similarly to Ethernet network interface 102I, Ethernet to data streamconversion module 202J is communicatively coupled to an Ethernet output212J of an external device that is an Ethernet adapter 108J and to atleast one digital communication link 110. In contrast to Ethernetnetwork interface 102I, Ethernet network interface clock unit 204J isnot coupled directly to Ethernet adapter clock unit 214J of Ethernetadapter 108J to provide and/or receive the master reference clockto/from the Ethernet adapter 108J. Instead, Ethernet network interface102J provides the master reference clock to the Ethernet to data streamconversion module 202J and the master reference clock is embedded inupstream signals from the Ethernet to data stream conversion module 202Jto the Ethernet output 212J of the Ethernet adapter 108J.

In particular, uplink signals can be clocked using the master clock,such that the master clock is embedded in the uplink signals. Then,Ethernet adapter clock unit 214J extracts the master clock from uplinksignals and distributes the master clock as appropriate in the Ethernetadapter 108J to establish a common clock with the distributed antennasystem 100 in the Ethernet adapter 108J. In exemplary embodiments wherethe master reference clock is provided from the Ethernet adapter 108J tothe distributed antenna system 100, the master reference clock can beembedded in the downlink signals by the Ethernet adapter clock unit 214Jso that the downlink signals communicated from the Ethernet output 212Jof the Ethernet adapter 108J to the Ethernet to data stream conversionmodule 202J can be extracted by the Ethernet network interface clockunit 204J and distributed as appropriate within the Ethernet networkinterface 102J and the distributed antenna system 100 generally.

In exemplary embodiments, the Ethernet to data stream conversion module202J and/or the Ethernet network interface clock unit 204J areimplemented using optional processor 206 and optional memory 208. Inexemplary embodiments, the optional power supply 210 provides power tothe various elements of the Ethernet network interface 102J.

FIGS. 3A-3C are block diagrams of exemplary embodiments of distributedantenna switches used in distributed antenna systems, such as theexemplary distributed antenna systems 100 described above. Each of FIGS.3A-3C illustrates a different embodiment of distributed antenna switch118, labeled distributed antenna switch 118A-118C respectively.

FIG. 3A is a block diagram of an exemplary distributed antenna switch118A including a data stream routing unit 302, electro-opticalconversion modules 304 (including electro-optical conversion module304-1, electro-optical conversion module 304-2, and any amount ofoptional electro-optical conversion modules 304 through optionalelectro-optical conversion module 304-A, and at least oneelectro-optical conversion module 306-1 (and any amount of optionalelectro-optical conversion modules 306 through optional electro-opticalconversion module 306-B). In exemplary embodiments, the data streamrouting unit 302 is implemented using optional processor 308 andoptional memory 310. In exemplary embodiments, the distributed antennaswitch 118A includes optional power supply 312 to power the variouselements of the distributed antenna switch 118A. In exemplaryembodiments, the distributed antenna switch 118A can be controlled by aseparate controller or another component of the system. In exemplaryembodiments the distributed antenna switch 118A is controlled eithermanually or automatically. In exemplary embodiments, the routes can bepre-determined and static. In other exemplary embodiments, the routescan dynamically change based on time of day, load, or other factors.

Each electro-optical conversion module 304 is communicatively coupled toa network interface 102 across a digital communication link 110. In theforward path, each electro-optical conversion module 304 is configuredto receive a downlink digitized data stream from at least one networkinterface 102 across a digital communication link 110. Specifically,electro-optical conversion module 304-1 is configured to receive adownlink digitized data stream from network interface 102-1 acrossdigital communication link 110-1, electro-optical conversion module304-2 is configured to receive a downlink digitized data stream fromnetwork interface 102-2 across digital communication link 110-2, andoptional electro-optical conversion module 304-A is configured toreceive a downlink digitized data stream from optional network interface102-A across optional digital communication link 110-A. Eachelectro-optical conversion module 304 is configured to convert thedownlink digitized data streams from optical to electrical signals,which are then passed onto the data stream routing unit 302. Similarlyin the reverse path, in exemplary embodiments each electro-opticalconversion module 304 is configured to receive an uplink digitized datastream in an electrical format from the data stream routing unit 302 andto convert them to an optical format for communication across a digitalcommunication link 110 to a network interface 102.

Generally in the forward path, the data stream routing unit 302 receivesdownlink data streams for a plurality of electro-optical conversionmodules 304 and aggregates a plurality of these downlink data streamsinto at least one downlink aggregate data stream that is routed to atleast one electro-optical conversion module 306 (such as electro-opticalconversion module 306-1) for eventual transmission to a remote antennaunit 104. In exemplary embodiments, the same or different downlinkaggregate data streams are routed to a plurality of electro-opticalconversion modules 306. In some embodiments, the data stream routingunit 302 is configured to aggregate and route data from a first subsetof network interfaces 102 into a first downlink aggregate data streamthat is transferred to at least a first remote antenna unit 104 and isfurther configured to aggregate and route data from a second subset ofnetwork interfaces 102 into a second downlink aggregate data stream thatis transferred to at least a second remote antenna unit 104. Inexemplary embodiments, the first and second subsets are mutuallyexclusive. In other exemplary embodiments, the first and second subsetspartially overlap. In other exemplary embodiments, the first and secondsubsets are identical. In other exemplary embodiments, data streams fromgreater numbers of subsets of network interfaces 102 are aggregated andcommunicated to greater numbers of remote antenna units 104.

Similarly in the reverse path, the data stream routing unit 302 receivesat least one uplink aggregate data stream from at least oneelectro-optical conversion module 306 (such as electro-opticalconversion module 306-1) from a remote antenna unit 104 and splits itinto a plurality of uplink data streams which are passed toelectro-optical conversion modules 304-1 for eventual communication to anetwork interface 102. In exemplary embodiments, the same or differentuplink aggregate data streams are received from a plurality ofelectro-optical conversion modules 306. In some embodiments, the datastream routing unit 302 is configured to receive, split apart, and routedata from a first uplink aggregate data stream from at least a firstremote antenna unit 104-1 to a first subset of electro-opticalconversion modules 304 destined for a first subset of network interfaces102 and is further configured to receive, split apart, and route datafrom a second uplink aggregate data stream from at least a second remoteantenna unit 104-2 to a second subset of electro-optical conversionmodules 304 destined for a second subset of network interfaces 102. Inexemplary embodiments, the first and second subsets are mutuallyexclusive. In other exemplary embodiments, the first and second subsetspartially overlap. In other exemplary embodiments, the first and secondsubsets are identical. In other exemplary embodiments, aggregate datastreams from greater numbers of remote antenna units 104 are split apartand communicated to greater numbers of subsets of network interfaces102.

Electro-optical conversion module 306 is communicatively coupled to aremote antenna unit 104 across a digital communication link 112. In theforward path, each electro-optical conversion module 304 is configuredto receive an aggregate downlink data stream in an electrical formatfrom the data stream routing unit 302. Specifically, electro-opticalconversion module 306-1 is configured to receive a first downlinkaggregate data stream in an electrical format from the data streamrouting unit 302, and optional electro-optical conversion module 306-Bis configured to receive a second downlink aggregate data stream fromdata stream routing unit 302. Each electro-optical conversion module 306is configured to convert the aggregate downlink data streams fromelectrical signals to optical signals, which are then communicatedacross a digital communication link 110 to a remote antenna unit 104.Similarly, in the reverse path, in exemplary embodiments eachelectro-optical conversion module 304 is configured to receive an uplinkaggregate digitized data stream from a remote antenna unit 104 across adigital communication link 110 in an optical format and to convert themto an electrical format for communication to the data stream routingunit 302.

FIG. 3B is a block diagram of an exemplary distributed antenna switch118B including data stream routing unit 302, optional processor 308,optional memory 310, and optional power supply 312. Distributed antennaswitch 118B includes similar components to distributed antenna switch118A and operates according to similar principles and methods asdistributed antenna switch 118A described above. The difference betweendistributed antenna switch 118B and distributed antenna switch 118A isthat distributed antenna switch 118B does not include anyelectro-optical conversion modules 304 or any electro-optical conversionmodules 306. Accordingly, the distributed antenna switch 118Bcommunicates using electrical signals with upstream network interfaces102 and downstream with remote units 104 through distributed switchingnetwork 106. In exemplary embodiments, the distributed antenna switch118B can be controlled by a separate controller or another component ofthe system. In exemplary embodiments the distributed antenna switch 118Bis controlled either manually or automatically. In exemplaryembodiments, the routes can be pre-determined and static. In otherexemplary embodiments, the routes can dynamically change based on timeof day, load, or other factors.

FIG. 3C is a block diagram of an exemplary distributed antenna switch118C including data stream routing unit 302, at least oneelectro-optical conversion module 306, optional processor 308, optionalmemory 310, and optional power supply 312. Distributed antenna switch118C includes similar components to distributed antenna switch 118A andoperates according to similar principles and methods as distributedantenna switch 118A described above. The difference between distributedantenna switch 118C and distributed antenna switch 118A is thatdistributed antenna switch 118C does not include any electro-opticalconversion modules 304. Accordingly, the distributed antenna switch 118Ccommunicates using electrical signals with upstream network interfaces102 and using optical signals with downstream remote antenna units 104through distributed switching network 106. Exemplary embodiments combineelectrical and optical communication in either the upstream and/ordownstream at the distributed antenna switch 118. In exemplaryembodiments, the distributed antenna switch 118C can be controlled by aseparate controller or another component of the system. In exemplaryembodiments the distributed antenna switch 118C is controlled eithermanually or automatically. In exemplary embodiments, the routes can bepre-determined and static. In other exemplary embodiments, the routescan dynamically change based on time of day, load, or other factors.

FIG. 4 is a block diagram of an exemplary embodiment of a master hostunit 120 used in distributed antenna systems, such as the exemplarydistributed antenna systems 100 described above. Exemplary master hostunit 120 includes at least two network interfaces 102 (including networkinterface 102-1, network interface 102-2, and any number of optionalnetwork interfaces 102 through optional network interface 102-A),distributed antenna switch 118B, at least one electro-optical conversionmodule 306 (including electro-optical conversion module 306-1 and anyamount of optional electro-optical conversion modules 306 throughelectro-optical conversion module 306-B), an optional master host clockunit 402, an optional processor 404, optional memory 406, and anoptional power supply 408. In exemplary embodiments, the networkinterfaces 102, distributed antenna switch 118B, the at least oneelectro-optical conversion module 306, and/or master host clock unit 402are implemented by optional processor 404 and memory 406. In exemplaryembodiments, power supply 408 provides power for the various componentsof the master host unit 120. In exemplary embodiments, the distributedantenna switch 118B can be controlled by a separate controller oranother component of the system. In exemplary embodiments thedistributed antenna switch 118B is controlled either manually orautomatically. In exemplary embodiments, the routes can bepre-determined and static. In other exemplary embodiments, the routescan dynamically change based on time of day, load, or other factors.

In the forward path, each network interface 102 receives downlinksignals from a respective external device 108, converts the downlinksignals into a downlink data stream, and communicates the downlink datastream to the distributed antenna switch 118B. In exemplary embodiments,the distributed antenna switch 118B aggregates the downlink data streamsand outputs the aggregate downlink data stream to the at least oneelectro-optical conversion module 306-1. In other embodiments, thedistributed antenna switch 118B aggregates and routes downlink datastreams received from respective network interfaces 102 in differentways. In exemplary embodiments, the electro-optical conversion module306-1 converts the aggregate downlink data stream output by thedistributed antenna switch from electrical format to optical format andoutputs it on optical communication medium 112-1. In exemplaryembodiments, electro-optical conversion modules 306 convert variousdownlink data streams output by the distributed antenna switch fromelectrical format to optical format and outputs them on opticalcommunication mediums 112.

In the reverse path, the electro-optical conversion module 306-1receives optical formatted uplink data streams from the opticalcommunication medium 112-1, converts them to electrical signals andpasses the electrically formatted uplink data streams to the distributedantenna switch 118B. In exemplary embodiments, the distributed antennaswitch splits apart, aggregates, and routes uplink data streams receivedfrom respective network interfaces 102 in different ways to variousnetwork interfaces 102. The network interfaces 102 then convert theuplink data streams into uplink signals that are passed onto therespective external devices 108.

In exemplary embodiments, the master host clock unit 402 extracts themaster reference clock from signal supplied by at least one externaldevice 108 and distributes this master clock with other external devices108 through the corresponding network interfaces 102. In exemplaryembodiments, the master host clock unit 402 generates a master referenceclock and distributes the generated master reference clock with externaldevices 108 through the corresponding network interfaces 102. Inexemplary embodiments, the master clock is also supplied to othercomponents of the distributed antenna system 100 in the downlink.

FIG. 5 is a block diagram of an exemplary embodiment of a remote antennaunit 104 used in distributed antenna systems, such as the exemplarydistributed antenna systems 100 described above. The remote antenna unit104 includes a data stream multiplexing unit 502, at least one radiofrequency (RF) conversion module 504 (including RF conversion module504-1 and any amount of optional RF conversion modules 504 throughoptional RF conversion module 504-C), optional electro-opticalconversion module 506, optional Ethernet interface 508, optional remoteantenna unit clock unit 510, optional processor 512, optional memory514, and optional power supply 516. In exemplary embodiments, datastream multiplexing unit 502, at least one RF conversion module 504,and/or the optional electro-optical conversion module 506 areimplemented at least in part by optional processor 512 and memory 514.In exemplary embodiments, optional power supply 516 is used to power thevarious components of the remote antenna unit 104.

In exemplary embodiments, data stream multiplexing unit 502 receives atleast one downlink data stream from at least one network interface 102through the distributed switching network 106. In exemplary embodiments,the at least one downlink data stream is received through the optionalelectro-optical conversion module 506 that converts the downlink datastream from an optical format to an electrical format. In exemplaryembodiments, more input lines and/or more electro-optical conversionmodules 506 are included in the remote antenna unit 104. In exemplaryembodiments, the data stream multiplexing unit 502 splits apart anaggregate downlink data stream into at least one downlink data streamthat is sent to RF conversion module 504-1 for eventual transmission asa radio frequency on antenna 114-1. In exemplary embodiments, the datastream multiplexing unit 502 splits apart the aggregate downlink datastream into a plurality of downlink data streams that are sent to aplurality of RF conversion modules 504 for eventual transmission asradio frequency signals at antennas 114.

In exemplary embodiments, data stream multiplexing unit 502 receives atleast one uplink data stream from at least one RF conversion module 504.In exemplary embodiments, the data stream multiplexing unit 502 receivesa plurality of uplink data streams from a plurality of RF conversionmodules 504. In exemplary embodiments, the data stream multiplexing unitaggregates at least one uplink data stream received from an RFconversion module 504-1 with another uplink data stream received fromanother RF conversion module 504. In exemplary embodiments, the datastream multiplexing unit 502 aggregates a plurality of uplink datastreams into a single aggregate uplink data stream. In exemplaryembodiments, the aggregate uplink data stream is provided to optionalelectro-optical conversion module 506 which converts the aggregateuplink data stream from electrical signals to optical signals beforecommunicating the aggregate uplink data stream to the distributedantenna switch 102 through the distributed switching network 106. Inother embodiments, the aggregate uplink data stream is communicated aselectrical signals toward the distributed antenna switch 102 through thedistributed switching network 106. In exemplary embodiments, theaggregate uplink signal is converted to optical signals at another placein the distributed antenna system 100.

In exemplary embodiments, the optional Ethernet interface 508 receives adownlink data stream from the data stream multiplexing unit 502 andconverts it to Ethernet packets and communicates the Ethernet packetswith an internet protocol network device. The optional Ethernetinterface 508 also receives Ethernet packets from the internet protocolnetwork device and converts them to an uplink data stream andcommunicates it to the data stream multiplexing unit 502.

In exemplary embodiments, the optional remote antenna unit clock unit510 extracts the master reference clock from the downlink data streamand uses this master clock within the remote antenna unit 104 toestablish a common time base in the remote antenna unit 104 with therest of the distributed antenna system 100. In exemplary embodiments,the optional remote antenna unit clock unit 510 generates a masterreference clock and distributes the generated master reference clock toother components of the distributed antenna system 100 (and even theexternal devices 108) in the upstream using the uplink data stream.

FIGS. 6A-6C are block diagrams of exemplary embodiments of RF conversionmodules 504 used in remote antenna units of distributed antenna systems,such as the exemplary remote antenna unit 100 described above. Each ofFIGS. 6A-6C are block diagrams of exemplary embodiments of RF conversionmodule 504, labeled RF conversion module 504A-504C respectively.

FIG. 6A is a block diagram of an exemplary RF conversion module 504Aincluding an optional data stream conditioner 602, an RF frequencyconverter 604, an optional RF conditioner 606, and an RF duplexer 608coupled to a single antenna 114.

The optional data stream conditioner 602 is communicatively coupled to adata stream multiplexing unit 502 and the radio frequency (RF) converter604. In the forward path, the optional data stream conditioner 602conditions the downlink data stream (for example, through amplification,attenuation, and filtering) received from the data stream multiplexingunit 502 and passes the downlink data stream to the RF converter 604. Inthe reverse path, the optional data stream conditioner 602 conditionsthe uplink data stream (for example, through amplification, attenuation,and filtering) received from the RF converter 604 and passes the uplinkdata stream to the data stream multiplexing unit 502.

The RF converter 604 is communicatively coupled to either the datastream multiplexing unit 502 or the optional data stream conditioner 602on one side and to either RF duplexer 608 or the optional RF conditioner606 on the other side. In the downstream, the RF converter 604 convertsa downlink data stream to downlink radio frequency (RF) signals andpasses the downlink RF signals onto either the RF duplexer 608 or theoptional RF conditioner 606. In the upstream, the RF converter 604converts uplink radio frequency (RF) signals received from either the RFduplexer 608 or the optional RF conditioner 606 to an uplink data streamand passes the uplink data stream to either the data stream multiplexingunit 502 or the optional data stream conditioner 602.

The RF duplexer 608 is communicatively coupled to either the RFfrequency converter 604 or the optional RF conditioner 606 on one sideand the antenna 114 on the other side. The RF duplexer 608 duplexes thedownlink RF signals with the uplink RF signals fortransmission/reception using the antenna 114.

FIG. 6B is a block diagram of an exemplary RF conversion module 504Bincluding an optional data stream conditioner 602, an RF frequencyconverter 604, and an optional RF conditioner 606 coupled to a downlinkantenna 114A and an uplink antenna 114B. RF conversion module 504Bincludes similar components to RF conversion module 504A and operatesaccording to similar principles and methods as RF conversion module 504Adescribed above. The difference between RF conversion module 504B and RFconversion module 504A is that RF conversion module 504B does notinclude RF duplexer 608 and instead includes separate downlink antenna114A used to transmit RF signals to at least one subscriber unit anduplink antenna 114B used to receive RF signals from at least onesubscriber unit.

FIG. 6C is a block diagram of an exemplary RF conversion module 504C-1and exemplary RF conversion module 504C-2 that share a single antenna114 through an RF diplexer 610. The RF conversion module 504C-1 includesan optional data stream conditioner 602-1, an RF frequency converter604-1, an optional RF conditioner 606-1, and an RF duplexer 608-1communicatively coupled to RF diplexer 610 that is communicativelycoupled to antenna 114. Similarly, the RF conversion module 504C-2includes an optional data stream conditioner 602-2, an RF frequencyconverter 604-2, an optional RF conditioner 606-2, and an RF duplexer608-2 communicatively coupled to RF diplexer 610 that is communicativelycoupled to antenna 114. Each of RF conversion module 504C-1 and 504C-2operate according to similar principles and methods as RF conversionmodule 504A described above. The difference between RF conversionmodules 504C-1 and 504C-2 and RF conversion module 504A is that RFconversion modules 504C-1 and 504C-2 are both coupled to a singleantenna 114 through RF diplexer 610. The RF diplexer 610 diplexes theduplexed downlink and uplink signals for both RF conversion module504C-1 and 504C-2 for transmission/reception using the single antenna114.

FIG. 7 is a block diagram of an exemplary embodiment of a hybriddistributed antenna system 700. Hybrid distributed antenna system 700includes a master host unit 120 having a plurality of network interfaces102 (including network interface 102-1, network interface 102-2, and anyamount of optional network interfaces 102 through optional networkinterface 102-A) and a distributed antenna switch 118C, at least onehybrid expansion unit 702 (including hybrid expansion unit 702-1,optional hybrid expansion unit 702-2 and any amount of additionaloptional hybrid expansion units 702 through optional hybrid expansionunit 702-H), at least one analog remote antenna unit 704 (includinganalog remote antenna unit 704-1 and any amount of optional analogremote antenna units 704 through analog remote antenna unit 704-L), andoptional digital expansion unit 706. Master host unit 120 includingnetwork interfaces 102 and distributed antenna switch 118C operate asdescribed above. The main differences between the hybrid distributedantenna system 700 and the distributed antenna systems 100 describedabove is the inclusion of at least one hybrid expansion unit 702 thatacts as the interface between the digital portion of the distributedantenna system 700 (between the master host unit 120 and the hybridexpansion unit 702) and the analog portion of the distributed antennasystem 700 (between the hybrid expansion unit 702 and the at least oneanalog remote antenna unit 704). In exemplary embodiments, thedistributed antenna switch 118C can be controlled by a separatecontroller or another component of the system. In exemplary embodimentsthe distributed antenna switch 118C is controlled either manually orautomatically. In exemplary embodiments, the routes can bepre-determined and static. In other exemplary embodiments, the routescan dynamically change based on time of day, load, or other factors.

In the forward path, the hybrid expansion unit 702 converts between thedigital downlink data stream provided by the distributed antenna switch118C across digital communication link 110 and analog downlink signalsthat are communicated to the at least one analog remote antenna unit704. In exemplary embodiments, the hybrid expansion unit 702 aggregates,splits apart, and routes downlink data streams converted to downlinkanalog signals to various analog remote antenna units 704. In exemplaryembodiments, the analog downlink signals are intermediate frequencyanalog signals communicated across an analog wired medium 710, such as acoaxial cable or twisted pair cabling. The analog remote antenna unit704 then converts the analog signals to radio frequency signals andcommunicates them with a subscriber unit.

In the reverse path, the analog remote antenna unit 704 receives radiofrequency signals from a subscriber unit and converts the radiofrequency signals to analog signals for transmission across the analogwired medium 710. The hybrid expansion unit 702 converts between analoguplink signals received from the analog remote antenna unit to an uplinkdata stream that is communicated to the distributed antenna switch 118Cacross digital communication link 110. In exemplary embodiments, thehybrid expansion unit 702 aggregates, splits apart, and routes uplinkanalog signals converted to uplink data streams to various ports of thedistributed antenna switch 118C or different master host units 120altogether. In exemplary embodiments, the analog uplink signals areintermediate frequency analog signals communicated across the analogwired medium 710.

FIG. 8 is a block diagram of an exemplary embodiment of a hybridexpansion unit 702 used in hybrid distributed antenna systems, such asthe hybrid distributed antenna system 700. Hybrid expansion unit 702includes a data stream multiplexing unit 802, a plurality of digital toanalog conversion units 804 (including digital to analog conversion unit804-1 and any number of optional digital to analog conversion units 804through digital to analog conversion unit 804-M), an analog multiplexingunit 806, optional electro-optical conversion modules 808 (includingoptional electro-optical conversion module 808-1 though optionalelectro-optical conversion module 808-N), an optional digital expansionclock unit 810, an optional analog domain reference clock unit 812, anoptional processor 814, optional memory 816, and an optional powersupply 818. In exemplary embodiments, the data stream multiplexing unit802, the digital to analog conversion units 804, the analog multiplexingunit 806, the digital expansion clock unit 810, and/or the analog domainreference clock unit 816 are at least in part implemented using optionalprocessor 814 and optional memory 816. In exemplary embodiments, theoptional power supply 818 provides power to the various elements of thehybrid expansion unit 702.

In the forward path, the data stream multiplexing unit 802 receivesdownlink data streams from distributed antenna switches 118C. Inexemplary embodiments, the downlink data streams are converted fromoptical signals to electrical signals by optional electro-opticalconversion modules 808. The data stream multiplexing unit 802 thenroutes the data streams to appropriate digital to analog conversionunits 804 for conversion to analog signals from digital data streams. Inexemplary embodiments, the digital to analog conversion units 804convert the downlink data streams into downlink intermediate frequencysignals. In exemplary embodiments, the analog multiplexing unit 806receives the downlink analog signals and routes them to appropriateanalog communication medium 710.

In the reverse path, the analog multiplexing unit 806 receives uplinkanalog signals from the analog communication media 710 and routes themto the appropriate digital to analog conversion unit 804 to be convertedto uplink data streams and passed to the data stream multiplexing unit802 for routing to the appropriate digital communication medium 110destined to a particular port of a distributed antenna switch 118C.

In exemplary embodiments, the digital expansion clock unit 810 extractsthe master reference clock from a downlink data stream received from thedistributed antenna switch 118C and passes it to the analog domainreference clock unit 812, which converts the master reference clock toan analog clock that is then embedded in the downlink analog signals atthe analog multiplexing unit 806. Accordingly, the reference clock canbe used within the hybrid expansion unit 702 and sent to the analogremote antenna units 704 for use by them. In other embodiments, themaster reference clock is received from one of the analog remote antennaunits 704 or another downstream component of the distributed antennasystem 700 and is extracted by the analog domain reference clock unit812 and provided to the digital expansion clock unit 810 which embeds itinto uplink digital data streams for communication to the distributedantenna switch 118C.

FIG. 9 is a block diagram of an exemplary embodiment of an analog remoteantenna unit 704 used in hybrid or analog distributed antenna systems,such as the exemplary hybrid distributed antenna system 700. The analogremote antenna unit includes an analog multiplexing unit 902, at leastone radio frequency (RF) conversion module 904 (including RF conversionmodule 904-1 and any amount of optional RF conversion modules 904through optional RF conversion module 904-0), optional Ethernetinterface 906, optional remote antenna unit clock unit 908, optionalprocessor 910, optional memory 912, and optional power supply 914. Inexemplary embodiments, analog multiplexing unit 902, at least one RFconversion module 904, and/or the remote antenna unit clock unit 908 areimplemented at least in part by optional processor 910 and optionalmemory 912. In exemplary embodiments, optional power supply 914 is usedto power the various components of the analog remote antenna unit 704.

In exemplary embodiments, analog multiplexing unit 902 receives at leastone multiplexed analog signal from at least one hybrid expansion unit702. In exemplary embodiments more input lines are included in theanalog remote antenna unit 704. In exemplary embodiments, the analogmultiplexing unit 904 splits apart an aggregate multiplexed downlinkanalog signal into at least one downlink analog signal that is sent toRF conversion module 904-1 for eventual transmission as a radiofrequency on antenna 114-1. In exemplary embodiments, the analogmultiplexing unit 902 splits apart the aggregate downlink analog signalsinto a plurality of downlink analog signals that are sent to a pluralityof RF conversion modules 904 for eventual transmission as radiofrequency signals at antennas 114.

In exemplary embodiments, analog multiplexing unit 902 receives at leastone uplink analog signal from at least one RF conversion module 904. Inexemplary embodiments, the analog multiplexing unit 902 receives aplurality of uplink analog signals from a plurality of RF conversionmodules 904. In exemplary embodiments, the analog multiplexing unit 902aggregates at least one uplink analog signal received from an RFconversion module 904-1 with another uplink analog signal received fromanother RF conversion module 904. In exemplary embodiments, the analogmultiplexing unit 902 aggregates a plurality of uplink analog signalsinto a single aggregate analog multiplexed signal. In exemplaryembodiments, the aggregate uplink data stream is communicated aselectrical signals to the hybrid expansion unit 702.

In exemplary embodiments, the optional remote antenna unit clock unit908 extracts the master reference clock from the downlink analog signaland uses this master clock within the analog remote antenna unit 704 toestablish a common time base in the remote antenna unit 704 with therest of the distributed antenna system 100. In exemplary embodiments,the optional remote antenna unit clock unit 908 generates a masterreference clock and distributes the generated master reference clock toother components of the distributed antenna system 100 (and even theexternal devices 108) in the upstream using the uplink analog signal.

In exemplary embodiments, the optional Ethernet interface 906 receives adownlink analog signal from the analog multiplexing unit 902 andconverts it to Ethernet packets and communicates the Ethernet packetswith an internet protocol network device. The optional Ethernetinterface 906 also receives Ethernet packets from the internet protocolnetwork device and converts them to an uplink analog signal andcommunicates it to the analog multiplexing unit 902.

FIGS. 10A-10C are block diagrams of exemplary embodiments of RFconversion modules 904 used in analog remote antenna units of hybrid oranalog distributed antenna systems, such as the exemplary remote antennaunit 700 described above. Each of FIGS. 10A-10C are block diagrams ofexemplary embodiments of RF conversion module 904, labeled RF conversionmodule 904A-904C respectively.

FIG. 10A is a block diagram of an exemplary RF conversion module 904Aincluding an optional analog intermediate frequency conditioner 1002, anRF frequency converter 1004, an optional RF conditioner 1006, and an RFduplexer 1008 coupled to a single antenna 114.

The optional analog intermediate frequency conditioner 1002 iscommunicatively coupled to a data stream multiplexing unit 502 and theradio frequency (RF) converter 1004. In the forward path, the optionalanalog intermediate frequency conditioner 1002 conditions the downlinkdata stream (for example, through amplification, attenuation, andfiltering) received from the data stream multiplexing unit 502 andpasses the downlink data stream to the RF converter 1004. In the reversepath, the optional analog intermediate frequency conditioner 1002conditions the uplink data stream (for example, through amplification,attenuation, and filtering) received from the RF converter 1004 andpasses the uplink data stream to the data stream multiplexing unit 502.

The RF converter 1004 is communicatively coupled to either the datastream multiplexing unit 502 or the optional analog intermediatefrequency conditioner 1002 on one side and to either RF duplexer 1008 orthe optional RF conditioner 1006 on the other side. In the downstream,the RF converter 1004 converts a downlink data stream to downlink radiofrequency (RF) signals and passes the downlink RF signals onto eitherthe RF duplexer 1008 or the optional RF conditioner 1006. In theupstream, the RF converter 1004 converts uplink radio frequency (RF)signals received from either the RF duplexer 1008 or the optional RFconditioner 1006 to an uplink data stream and passes the uplink datastream to either the data stream multiplexing unit 502 or the optionalanalog intermediate frequency conditioner 1002.

The RF duplexer 1008 is communicatively coupled to either the RFfrequency converter 1004 or the optional RF conditioner 1006 on one sideand the antenna 114 on the other side. The RF duplexer 1008 duplexes thedownlink RF signals with the uplink RF signals fortransmission/reception using the antenna 114.

FIG. 10B is a block diagram of an exemplary RF conversion module 904Bincluding an optional analog intermediate frequency conditioner 1002, anRF frequency converter 1004, and an optional RF conditioner 1006 coupledto a downlink antenna 114A and an uplink antenna 114B. RF conversionmodule 904B includes similar components to RF conversion module 904A andoperates according to similar principles and methods as RF conversionmodule 904A described above. The difference between RF conversion module904B and RF conversion module 904A is that RF conversion module 904Bdoes not include RF duplexer 1008 and instead includes separate downlinkantenna 114A used to transmit RF signals to at least one subscriber unitand uplink antenna 114B used to receive RF signals from at least onesubscriber unit.

FIG. 10C is a block diagram of an exemplary RF conversion module 904C-1and exemplary RF conversion module 904C-2 that share a single antenna114 through an RF diplexer 1010. The RF conversion module 904C-1includes an optional analog intermediate frequency conditioner 1002-1,an RF frequency converter 1004-1, an optional RF conditioner 1006-1, andan RF duplexer 1008-1 communicatively coupled to RF diplexer 1010 thatis communicatively coupled to antenna 114. Similarly, the RF conversionmodule 904C-2 includes an optional analog intermediate frequencyconditioner 1002-2, an RF frequency converter 1004-2, an optional RFconditioner 1006-2, and an RF duplexer 1008-2 communicatively coupled toRF diplexer 1010 that is communicatively coupled to antenna 114. Each ofRF conversion module 904C-1 and 904C-2 operate according to similarprinciples and methods as RF conversion module 904A described above. Thedifference between RF conversion modules 904C-1 and 904C-2 and RFconversion module 904A is that RF conversion modules 904C-1 and 904C-2are both coupled to a single antenna 114 through RF diplexer 1010. TheRF diplexer 1010 diplexes the duplexed downlink and uplink signals forboth RF conversion module 904C-1 and 904C-2 for transmission/receptionusing the single antenna 114.

FIG. 11 is a flow diagram illustrating one exemplary embodiment of amethod 1100 of sourcing a master reference clock for a base stationnetwork interface from a distributed antenna system. Exemplary method1100 begins at block 1102 with receiving a first downlink signal from afirst external device external to a distributed antenna system via afirst network interface unit. Exemplary method 1100 proceeds to block1104 with converting the first downlink signal into a first downlinkdata stream at the first network interface unit. In exemplaryembodiments, the first downlink data stream is a baseband data stream.In exemplary implementations, the baseband data stream includesquadrature samples of I/Q pairs.

Exemplary method 1100 proceeds to block 1106 with receiving a seconddownlink signal from a second external device external to thedistributed antenna system via a second network interface unit.Exemplary method 1100 proceeds to block 1108 with converting the seconddownlink signal into a second downlink data stream at the second networkinterface unit. In exemplary embodiments, the second downlink datastream is a baseband data stream. In exemplary implementations, thebaseband data stream includes quadrature samples of I/Q pairs.

Exemplary method 1100 proceeds to block 1110 with communicating thefirst downlink data stream from the first network interface unit to atleast one of a first remote antenna unit and an intermediary device.Exemplary method 1100 proceeds to block 1112 with converting at leastone of the first downlink data stream and a first downlink signalderived from the first downlink data stream at the intermediary deviceinto a first radio frequency band signal at a first remote antenna unit.Exemplary method 1100 proceeds to block 1114 with transmitting the firstradio frequency band signal to the first subscriber unit at the firstremote antenna unit.

Exemplary method 1100 proceeds to block 1116 with transmitting a masterreference clock to the first external device through the first networkinterface unit. In exemplary embodiments, this includes transmittinguplink signals to the first external device through the first basestation network interface unit, wherein the uplink signals are clockedusing the master reference clock such that the master reference clock isembedded in the uplink signals. Exemplary embodiments of method 1100further include locking a reference clock of the first device of thedevices external to the distributed antenna system to the masterreference clock embedded in the uplink signals. In exemplaryembodiments, transmitting the master reference clock to the first deviceof the devices external to the distributed antenna system includestransmitting the master reference clock across a separate masterreference clock channel.

Exemplary embodiments of method 1100 further include generating themaster reference clock within the distributed antenna system. Exemplaryembodiments of method 1100 further include deriving the master referenceclock from the second external device through the second base stationnetwork interface. In exemplary embodiments, this includes locking themaster reference clock to a clock embedded in the second downlinksignals received from the second external device.

Exemplary embodiments of method 1100 further include communicating thefirst downlink data stream to a hybrid expansion unit communicativelycoupled between the first base station network interface unit and thefirst downlink data stream at the hybrid expansion unit; converting thefirst downlink data stream to the first downlink signal derived from thefirst downlink data stream at the hybrid expansion unit; communicatingthe first downlink signal derived from the first downlink data streamfrom the hybrid expansion unit to the first remote antenna unit; andconverting the first downlink signal derived from the first downlinkdata stream into a first radio frequency band signal at the first remoteantenna unit. In exemplary embodiments, the first downlink signalderived from the first downlink data stream is a downlink analogintermediate frequency signal.

Exemplary embodiments of method 1100 further include communicating thesecond downlink data stream from the second base station networkinterface unit to the first remote antenna unit; converting the seconddownlink data stream into a second radio frequency band signal at thefirst remote antenna unit; and transmitting the second radio frequencyband signal to a second subscriber unit at the first remote antennaunit.

Exemplary embodiments of method 1100 further include communicating thesecond downlink data stream from the second base station networkinterface unit to a hybrid expansion unit communicatively coupledbetween the second base station network interface unit and the firstremote antenna unit; converting the second downlink data stream to asecond downlink signal derived from the first downlink data stream atthe hybrid expansion unit; communicating the second downlink signalderived from the second downlink data stream from the hybrid expansionunit to the first remote antenna unit; converting the second downlinksignal derived from the second downlink data stream into a second radiofrequency band signal at the first remote antenna unit; and transmittingthe second radio frequency band signal to a second subscriber unit atthe first remote antenna unit.

Exemplary embodiments of method 1100 further include communicating thesecond downlink data stream from the second base station networkinterface unit to a second remote antenna unit; converting the firstdownlink data stream into a second radio frequency band signal at thesecond remote antenna unit; and transmitting the second radio frequencyband signal to a second subscriber unit at the second remote antennaunit.

Exemplary embodiments of method 1100 further include communicating thesecond downlink data stream from the second base station networkinterface unit to a hybrid expansion unit communicatively coupledbetween the second base station network interface unit and the firstremote antenna unit; converting the second downlink data stream to asecond downlink signal derived from the first downlink data stream atthe hybrid expansion unit; communicating the second downlink signalderived from the second downlink data stream from the hybrid expansionunit to the first remote antenna unit; converting the second downlinksignal derived from the second downlink data stream into a second radiofrequency band signal at the second remote antenna unit; andtransmitting the second radio frequency band signal to a secondsubscriber unit at the second remote antenna unit.

Exemplary embodiments of method 1100 further include communicating thefirst downlink data stream from the first base station network interfaceunit to a distributed antenna switch communicatively coupled between thefirst base station network interface unit and the first distributedantenna switch; communicating the second downlink data stream from thesecond base station network interface unit to the distributed antennaswitch communicatively coupled between the second base station networkinterface unit and the second distributed antenna switch; aggregatingthe first downlink data stream with the second downlink data stream intoan aggregate downlink data stream at the distributed antenna switch;communicating the aggregate downlink data stream to the first remoteantenna unit; and extracting the first downlink data stream from theaggregate downlink data stream at the first remote antenna unit.

Exemplary embodiments of method 1100 further include receiving a firstuplink radio frequency band signal from the first subscriber unit at thefirst remote antenna unit; converting the first uplink radio frequencyband signal to a first uplink data stream at the first remote antennaunit; communicating the first uplink data stream from the first remoteantenna unit to the first base station network interface unit;converting the first uplink data stream into first uplink signals at thefirst base station network interface; and communicating the first uplinksignals to the first external device at the first base station networkinterface.

Exemplary embodiments of method 1100 further include receiving a firstuplink radio frequency band signal from the first subscriber unit at thefirst remote antenna unit; converting the first uplink radio frequencyband signal to a first uplink analog intermediate frequency signal atthe first remote antenna unit; communicating the first analogintermediate frequency signal from the first remote antenna unit to ahybrid expansion unit communicatively coupled between the first basestation network interface and the first remote antenna unit; convertingthe first uplink analog intermediate frequency signal to a first uplinkdata stream at the hybrid expansion unit; communicating the first uplinkdata stream from the hybrid expansion unit to the first base stationnetwork interface unit; converting the first uplink data stream intofirst uplink signals at the first base station network interface; andcommunicating the first uplink signals to the first external device atthe first base station network interface.

Any of the processors described above may include or function withsoftware programs, firmware or other computer readable instructions forcarrying out various methods, process tasks, calculations, and controlfunctions, described herein. These instructions are typically stored onany appropriate computer readable medium used for storage of computerreadable instructions or data structures. The computer readable mediumcan be implemented as any available media that can be accessed by ageneral purpose or special purpose computer or processor, or anyprogrammable logic device. Suitable processor-readable media may includestorage or memory media such as magnetic or optical media. For example,storage or memory media may include conventional hard disks, CompactDisk-Read Only Memory (CD-ROM), volatile or non-volatile media such asRandom Access Memory (RAM) (including, but not limited to, SynchronousDynamic Random Access Memory (SDRAM), Double Data Rate (DDR) RAM, RAMBUSDynamic RAM (RDRAM), Static RAM (SRAM), etc.), Read Only Memory (ROM),Electrically Erasable Programmable ROM (EEPROM), and flash memory, etc.Suitable processor-readable media may also include transmission mediasuch as electrical, electromagnetic, or digital signals, conveyed via acommunication medium such as a network and/or a wireless link.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement, which is calculated to achieve the same purpose,may be substituted for the specific embodiments shown. Therefore, it ismanifestly intended that this invention be limited only by the claimsand the equivalents thereof.

Example Embodiments

Example 1 includes a distributed antenna system comprising: a first basestation network interface unit configured to receive first downlinksignals from a first external device external to the distributed antennasystem and to convert the first downlink signals into a first downlinkdata stream; a second base station network interface unit configured toreceive second downlink signals from a second external device externalto the distributed antenna system and to convert the second downlinksignals into a second downlink data stream; a first remote antenna unitcommunicatively coupled to the first base station network interface unitand configured to receive at least one of the first downlink data streamfrom the first base station network interface unit and a first downlinksignal derived from the first downlink data stream; the first remoteantenna unit having a first radio frequency converter configured toconvert at least one of the first downlink data stream and the firstdownlink signal derived from the first downlink data stream into a firstradio frequency band signal and a first radio frequency antennaconfigured to transmit the first radio frequency band signal to a firstsubscriber unit; and wherein the distributed antenna system isconfigured to transmit a master reference clock to the first externaldevice.

Example 2 includes the distributed antenna system of Example 1, whereinthe distributed antenna system is configured to generate the masterreference clock internally.

Example 3 includes the distributed antenna system of any of Examples1-2, wherein the distributed antenna system is configured to derive themaster reference clock from the second external device.

Example 4 includes the distributed antenna system of Example 3, whereinthe distributed antenna system is configured to derive the masterreference clock from the second external device by being configured tolock the master reference clock to a clock embedded in the seconddownlink signals received from the second external device.

Example 5 includes the distributed antenna system of any of Examples1-4, wherein the distributed antenna system is configured to transmitthe master reference clock to the first external device by beingconfigured to transmit first uplink signals to the first external devicethrough the first base station network interface unit, wherein the firstuplink signals are clocked using the master reference clock such thatthe master reference clock is embedded in the uplink signals.

Example 6 includes the distributed antenna system of any of Examples4-5, wherein the first external device is configured to lock its clockto the master reference clock embedded in the first uplink signals.

Example 7 includes the distributed antenna system of any of Examples1-6, wherein the distributed antenna system is configured to transmitthe master reference clock to the first external device by beingconfigured to transmit the master reference clock across a separatemaster reference clock channel.

Example 8 includes the distributed antenna system of any of Examples1-7, further comprising: a hybrid expansion unit communicatively coupledbetween the first base station network interface unit and the firstremote antenna unit and configured to receive the first downlink datastream and convert the first downlink data stream to the first downlinksignal derived from the first downlink data stream; wherein the firstremote antenna unit is further configured to receive the first downlinksignal derived from the first downlink data stream and to convert thefirst downlink signal derived from the first downlink data stream intothe second radio frequency band signal.

Example 9 includes the distributed antenna system of Example 8, whereinthe first downlink signal derived from the first downlink data stream isa downlink analog intermediate frequency signal.

Example 10 includes the distributed antenna system of any of Examples1-9, wherein the first remote antenna unit is further communicativelycoupled to the second base station network interface unit and configuredto receive at least one of the second downlink data stream from thesecond base station network interface unit and a second downlink signalderived from the second downlink data stream; the first remote antennaunit further having a second radio frequency converter configured toconvert at least one of the second downlink data stream and the seconddownlink signal derived from the second downlink data stream into asecond radio frequency band signal and a second radio frequency antennaconfigured to transmit the second radio frequency band signal to asecond subscriber unit.

Example 11 includes the distributed antenna system of any of Examples1-10, wherein the first remote antenna unit is further communicativelycoupled to the second base station network interface unit and configuredto receive at least one of the second downlink data stream from thesecond base station network interface unit and a second downlink signalderived from the second downlink data stream; the first remote antennaunit further having a second radio frequency converter configured toconvert at least one of the second downlink data stream and the seconddownlink signal derived from the second downlink data stream into asecond radio frequency band signal; and wherein the first radiofrequency antenna is further configured to transmit the second radiofrequency band signal to a second subscriber unit.

Example 12 includes the distributed antenna system of any of Examples1-11, further comprising a second remote antenna unit communicativelycoupled to the second base station network interface unit and configuredto receive at least one of the second downlink data stream from thesecond base station network interface unit and a second downlink signalderived from the second downlink data stream; and the second remoteantenna unit further having a second radio frequency converterconfigured to convert at least one of the second downlink data streamand the second downlink signal derived from the second downlink datastream into a second radio frequency band signal and a second radiofrequency antenna configured to transmit the second radio frequency bandsignal to a second subscriber unit.

Example 13 includes the distributed antenna system of any of Examples1-12, further comprising: a distributed antenna switch communicativelycoupled between both the first base station network interface unit andthe second base station network interface unit and the first remoteantenna unit, the distributed antenna switch configured to receive thefirst downlink data stream from the first base station network interfaceunit and the second downlink data stream from the second base stationnetwork interface unit and to aggregate the first downlink data streamwith the second downlink data stream into an aggregate downlink datastream; the distributed antenna switch further configured to transmitthe aggregate downlink data stream to the first remote antenna unit; andthe first remote antenna unit further configured to receive theaggregate downlink data stream and to extract the first downlink datastream from the aggregate downlink data stream.

Example 14 includes the distributed antenna system of Example 13,further comprising a second remote antenna unit communicatively coupledto the second base station network interface unit through thedistributed antenna switch and configured to receive aggregate downlinkdata stream and to extract the second downlink data stream from thesecond aggregate downlink data stream; the second remote antenna unitfurther having a second radio frequency converter configured to convertthe second downlink data stream into a second radio frequency bandsignal and a second radio frequency antenna configured to transmit thesecond radio frequency band signal to a second subscriber unit.

Example 15 includes the distributed antenna system of any of Examples1-14, wherein the first radio frequency antenna is further configured toreceive a first uplink radio frequency band signal from the firstsubscriber unit; wherein the first radio frequency converter is furtherconfigured to convert the first uplink radio frequency band signal to afirst uplink data stream; wherein the first remote antenna unit isfurther configured to communicate the first uplink data stream to thefirst base station network interface unit; wherein the first basestation network interface unit is configured to receive the first uplinkdata stream from the first remote antenna unit; wherein the firstnetwork interface is configured to convert the first uplink data streaminto first uplink signals; and wherein the first base station networkinterface unit is configured to communicate the first uplink signals tothe first external device.

Example 16 includes the distributed antenna system of any of Examples1-15, wherein the first radio frequency antenna is further configured toreceive a first uplink radio frequency band signal from the firstsubscriber unit; wherein the first radio frequency converter is furtherconfigured to convert the first uplink radio frequency band signal to afirst uplink analog intermediate frequency signal; wherein the firstremote antenna unit is further configured to communicate the firstuplink analog intermediate frequency signals to a hybrid expansion unit;wherein the hybrid expansion unit is configured to receive the firstuplink analog intermediate frequency signals from the first remoteantenna unit; wherein the hybrid expansion unit is configured to convertthe first uplink analog intermediate frequency signals to a first uplinkdata stream; wherein the hybrid expansion unit is configured tocommunicate the first uplink data stream to the first base stationnetwork interface unit; wherein the first base station network interfaceunit is configured to receive the first uplink data stream from thehybrid expansion unit; wherein the first network interface is configuredto convert the first uplink data stream into first uplink signals; andwherein the first base station network interface unit is configured tocommunicate the first uplink signals to the first external device.

Example 17 includes the distributed antenna system of any of Examples1-16, wherein the first external device is a base band unit of awireless access base station.

Example 18 includes the distributed antenna system of any of Examples1-17, wherein the first external device is a Common Public RadioInterface (CPRI) base station, wherein the first base station networkinterface unit is a CPRI converter interface communicatively coupled toa CPRI base station, the CPRI converter interface configured to receiveCPRI data from the CPRI base station, the CPRI converter interfacefurther configured to convert the CPRI data into a first downlink datastream of the plurality of downlink data streams.

Example 19 includes the distributed antenna system of any of Examples1-18, wherein the first downlink data stream is a baseband data stream.

Example 20 includes the distributed antenna system of Example 19,wherein the baseband data stream includes quadrature samples of I/Qpairs.

Example 21 includes a method comprising: receiving a first downlinksignal from a first external device external to a distributed antennasystem via a first base station network interface unit; converting thefirst downlink signal into a first downlink data stream at the firstbase station network interface unit; receiving a second downlink signalfrom a second external device external to the distributed antenna systemvia a second base station network interface unit; converting the seconddownlink signal into a second downlink data stream at the second basestation network interface unit; communicating the first downlink datastream from the first base station network interface unit to at leastone of a first remote antenna unit and an intermediary device;converting at least one of the first downlink data stream and a firstdownlink signal derived from the first downlink data stream at theintermediary device into a first radio frequency band signal at thefirst remote antenna unit; transmitting the first radio frequency bandsignal to a first subscriber unit at the first remote antenna unit;transmitting a master reference clock to the first external devicethrough the first base station network interface unit.

Example 22 includes the method of Example 21, further comprising:generating the master reference clock within the distributed antennasystem.

Example 23 includes the method of any of Examples 21-22, furthercomprising: deriving the master reference clock from the second externaldevice through the second base station network interface unit.

Example 24 includes the method of Example 23, wherein deriving themaster reference clock from the second external device through thesecond base station network interface unit includes: locking the masterreference clock to a clock embedded in the second downlink signalsreceived from the second external device.

Example 25 includes the method of any of Examples 21-24, whereintransmitting the master reference clock to the first external deviceincludes transmitting uplink signals to the first external devicethrough the first base station network interface unit, wherein theuplink signals are clocked using the master reference clock such thatthe master reference clock is embedded in the uplink signals.

Example 26 includes the method of Example 25, further comprising:locking a reference clock of the first device of the devices external tothe distributed antenna system to the master reference clock embedded inthe uplink signals.

Example 27 includes the method of any of Examples 21-26, whereintransmitting the master reference clock to the first device of thedevices external to the distributed antenna system includes transmittingthe master reference clock across a separate master reference clockchannel.

Example 28 includes the method of any of Examples 21-27, furthercomprising: communicating the first downlink data stream to a hybridexpansion unit communicatively coupled between the first base stationnetwork interface unit and the first remote antenna unit; converting thefirst downlink data stream to the first downlink signal derived from thefirst downlink data stream at the hybrid expansion unit; communicatingthe first downlink signal derived from the first downlink data streamfrom the hybrid expansion unit to the first remote antenna unit; andconverting the first downlink signal derived from the first downlinkdata stream into a first radio frequency band signal at the first remoteantenna unit.

Example 29 includes the method of Example 28, wherein the first downlinksignal derived from the first downlink data stream is a downlink analogintermediate frequency signal.

Example 30 includes the method of any of Examples 21-29, furthercomprising: communicating the second downlink data stream from thesecond base station network interface unit to the first remote antennaunit; converting the second downlink data stream into a second radiofrequency band signal at the first remote antenna unit; and transmittingthe second radio frequency band signal to a second subscriber unit atthe first remote antenna unit.

Example 31 includes the method of any of Examples 21-30, furthercomprising: communicating the second downlink data stream from thesecond base station network interface unit to a hybrid expansion unitcommunicatively coupled between the second base station networkinterface unit and the first remote antenna unit; converting the seconddownlink data stream to a second downlink signal derived from the firstdownlink data stream at the hybrid expansion unit; communicating thesecond downlink signal derived from the second downlink data stream fromthe hybrid expansion unit to the first remote antenna unit; convertingthe second downlink signal derived from the second downlink data streaminto a second radio frequency band signal at the first remote antennaunit; and transmitting the second radio frequency band signal to asecond subscriber unit at the first remote antenna unit.

Example 32 includes the method of any of Examples 21-31, furthercomprising: communicating the second downlink data stream from thesecond base station network interface unit to a second remote antennaunit; converting the first downlink data stream into a second radiofrequency band signal at the second remote antenna unit; andtransmitting the second radio frequency band signal to a secondsubscriber unit at the second remote antenna unit.

Example 33 includes the method of any of Examples 21-32, furthercomprising: communicating the second downlink data stream from thesecond base station network interface unit to a hybrid expansion unitcommunicatively coupled between the second base station networkinterface unit and the first remote antenna unit; converting the seconddownlink data stream to a second downlink signal derived from the firstdownlink data stream at the hybrid expansion unit; communicating thesecond downlink signal derived from the second downlink data stream fromthe hybrid expansion unit to the first remote antenna unit; andconverting the second downlink signal derived from the second downlinkdata stream into a second radio frequency band signal at the secondremote antenna unit; and transmitting the second radio frequency bandsignal to a second subscriber unit at the second remote antenna unit.

Example 34 includes the method of any of Examples 21-33, furthercomprising: communicating the first downlink data stream from the firstbase station network interface unit to a distributed antenna switchcommunicatively coupled between the first base station network interfaceunit and the first distributed antenna switch; communicating the seconddownlink data stream from the second base station network interface unitto the distributed antenna switch communicatively coupled between thesecond base station network interface unit and the second distributedantenna switch; aggregating the first downlink data stream with thesecond downlink data stream into an aggregate downlink data stream atthe distributed antenna switch; communicating the aggregate downlinkdata stream to the first remote antenna unit; and extracting the firstdownlink data stream from the aggregate downlink data stream at thefirst remote antenna unit.

Example 35 includes the method of any of Examples 21-34, furthercomprising: receiving a first uplink radio frequency band signal fromthe first subscriber unit at the first remote antenna unit; convertingthe first uplink radio frequency band signal to a first uplink datastream at the first remote antenna unit; communicating the first uplinkdata stream from the first remote antenna unit to the first base stationnetwork interface unit; converting the first uplink data stream intofirst uplink signals at the first base station network interface; andcommunicating the first uplink signals to the first external device atthe first base station network interface.

Example 36 includes the method of any of Examples 21-35, furthercomprising: receiving a first uplink radio frequency band signal fromthe first subscriber unit at the first remote antenna unit; convertingthe first uplink radio frequency band signal to a first uplink analogintermediate frequency signal at the first remote antenna unit;communicating the first analog intermediate frequency signal from thefirst remote antenna unit to a hybrid expansion unit communicativelycoupled between the first base station network interface and the firstremote antenna unit; converting the first uplink analog intermediatefrequency signal to a first uplink data stream at the hybrid expansionunit; communicating the first uplink data stream from the hybridexpansion unit to the first base station network interface unit;converting the first uplink data stream into first uplink signals at thefirst base station network interface; and communicating the first uplinksignals to the first external device at the first base station networkinterface.

Example 37 includes the method of any of Examples 21-36, wherein thefirst downlink data stream is a baseband data stream.

Example 38 includes the method of Example 37, wherein the baseband datastream includes quadrature samples of I/Q pairs.

Example 39 includes a base station comprising: a base station networkinterface configured to be communicatively coupled to a correspondingbase station network interface of a distributed antenna system andconfigured to communicate signals with the distributed antenna system; aclocking unit configured to receive a master clock signal from thedistributed antenna system; and wherein the base station is furtherconfigured to synchronize itself with the distributed antenna systemusing the master clock signal from the distributed antenna system.

Example 40 includes the base station of Example 39, wherein the clockingunit is configured to receive the master clock signal from thedistributed antenna system by being configured to lock to the masterclock embedded in an uplink signal received from the distributed antennasystem.

Example 41 includes the base station of any of Examples 39-40, whereinthe clocking unit is configured to receive the master clock signal fromthe first external device across a separate master reference clockchannel.

Example 42 includes the base station of any of Examples 39-41, whereinthe master reference clock is generated within the distributed antennasystem.

Example 43 includes the base station of any of Examples 39-42, whereinthe master reference clock is derived from an device external to thedistributed antenna system.

What is claimed is:
 1. A network interface for use within a distributedantenna system, the network interface comprising: circuitry configuredto: receive a downlink digital communication signal from an externaldevice external to the distributed antenna system, wherein a referenceclock is embedded in the downlink digital communication signal; generatea master reference clock for the distributed antenna system using thereference clock embedded in the downlink digital communication signal;convert the downlink digital communication signal into a downlinksignal; communicate the downlink signal toward a remote antenna unitwithin the distributed antenna system; and wherein the distributedantenna system is configured to distribute the master reference clock tovarious components of the distributed antenna system to keep the variouscomponents of the distributed antenna system locked to a single clock,wherein the various components of the distributed antenna system includethe remote antenna unit.
 2. The network interface of claim 1, whereinthe circuitry is configured to generate the master reference clock atleast in part by being configured to lock the master reference clock tothe reference clock embedded in the downlink digital communicationsignal.
 3. The network interface of claim 1, wherein the external deviceis a base band unit of a wireless access base station.
 4. The networkinterface of claim 1, wherein the external device is a Common PublicRadio Interface (CPRI) base station, wherein the network interface is aCPRI converter interface communicatively coupled to the CPRI basestation, the CPRI converter interface configured to receive CPRI datafrom the CPRI base station, the CPRI converter interface furtherconfigured to convert the CPRI data into a first downlink data stream ofa plurality of downlink data streams.
 5. The network interface of claim1, wherein the downlink signal is a data stream.
 6. The networkinterface of claim 1, wherein the downlink signal is a baseband datastream.
 7. The network interface of claim 1, wherein the remote antennaunit includes an antenna for communicating wirelessly with at least onesubscriber unit.
 8. A base station comprising: circuitry configured to:embed a reference clock in a downlink digital communication signal;communicate the downlink digital communication signal to a networkinterface of a distributed antenna system; wherein the distributedantenna system is configured to generate a master reference clock forthe distributed antenna system using the reference clock embedded in thedownlink digital communication signal and to distribute the masterreference clock to various components of the distributed antenna systemto keep the various components of the distributed antenna system lockedto a single master clock.
 9. The base station of claim 8, wherein thebase station is a base band unit of a wireless access base station. 10.The base station of claim 8, wherein the base station is a Common PublicRadio Interface (CPRI) base station, wherein the network interface is aCPRI converter interface communicatively coupled to the CPRI basestation, the CPRI converter interface configured to receive CPRI datafrom the CPRI base station, the CPRI converter interface furtherconfigured to convert the CPRI data into a first downlink data stream ofa plurality of downlink data streams.
 11. A method comprising: embeddinga reference clock in a downlink digital communication signal at anexternal device external to a distributed antenna system; communicatingthe downlink digital communication signal from the external device to anetwork interface of the distributed antenna system; generating a masterreference clock for the distributed antenna system at the networkinterface using the reference clock embedded in the downlink digitalcommunication signal; converting the downlink digital communicationsignal into a downlink signal at the network interface; communicatingthe downlink signal toward a remote antenna unit within the distributedantenna system; and distributing the master reference clock from thenetwork interface to various components of the distributed antennasystem to keep the various components of the distributed antenna systemlocked to a single clock, wherein the various components of thedistributed antenna system include the remote antenna unit.
 12. Themethod of claim 11, wherein generating the master reference clock occursat least in party by locking the master reference clock to the referenceclock embedded in the downlink digital communication signal.
 13. Themethod of claim 11, wherein the external device is a base band unit of awireless access base station.
 14. The method of claim 11, wherein theexternal device is a Common Public Radio Interface (CPRI) base station,wherein the network interface is a CPRI converter interfacecommunicatively coupled to the CPRI base station, the CPRI converterinterface configured to receive CPRI data from the CPRI base station,the CPRI converter interface further configured to convert the CPRI datainto a first downlink data stream of a plurality of downlink datastreams.
 15. The method of claim 11, wherein the downlink signal is adata stream.
 16. The method of claim 11, wherein the downlink signal isa baseband data stream.
 17. The method of claim 11, further comprising:communicating wirelessly from the remote antenna unit of the distributedantenna system with at least one subscriber unit.